Blower for cooling an internal-combustion engine and scavenging or supercharging



Feb. 28, 1956 EN 2,736,301

BLOWER FOR COOLING AN INTERNAL-COMBUSTION ENGINE AND SCAVENGING OR SUPERCHARGING Filed Aug. 11, 1950 2 Sheets-Sheet 1 Feb. 28, 1956 Filed Aug. 11. 1950 B. MEDENUS 2,736,301 BLOWER FOR COOLING AN INTERNAL-COMBUSTION ENGINE AND SCAVENGING OR SUPERCHARGING 2 Sheets-Sheet 2 0 v lnven/or:

'40 x 15 W W \45 y E A United States Patent Ofifice 1 2,736,301 P en ed Fe 28., .1956

Bernhard Medenus, Koln-Kalk, Germany, assignor to Kliiclmer-Humboldt-Deutz A. G., Koln am Rhine, Germany Application August 11, 1950, Serial No. 178,795 In Germany April 2, 1949 Public Law 619, August 23, 1954 Patent expires August 23, 1969 3 Claims. (Cl. 123-41. 65)

The invention relates to internal combustion engines with one or several blowers driven from the engine crank shaft for cooling, scavenging, or supercharging.

Such blowers, especially those for scavenging or supercharging in high-speed engines, have high revolving speeds up to 30,000 revolutions per minute. At such a high speed, the blower drive must satisfy exacting mechanical requirements. The high-speed portion of the blower driving transmission must be accurately manufactured and carefully journalled. This applies especially to the last step of the transmission immediately ahead of the blower. Since, as a rule, the rotor of the blower is journaled in a blower housing detachably connected with the engine frame, considerable difficulties are met as regards the meshing performance of the last gear step ahead of the blower. Due to inevitable inaccuracies of assembly, the coaction of the pinion on the blower shaft withthe appertaining driving gear may leave much to be desired.

it is an object of the invention to overcome these difiiculties. More specifically, it is an object of the invention to simplify the work needed for assembling the blower housing and blower transmission with the frame or main housing of the engine and to secure an accurate meshing performance of the high-speed gear stage immediately adjacent to the blower.

To achieve these objects, and in accordance with a feature of the invention, the last high-speed portion of the blower transmission and the blower rotor driven thereby are disposed and journalled in a fixed bearing relation to each other within a common housing detachably mounted on the engine frame.

The foregoing and more specific objects and features of the invention will be apparent from the following description in conjunction with the two embodiments exemplified by the drawing in which:

Figure 1 shows an axial section through a six-cylinder V-type diesel engine,

Fig. 2 shows a partial view of another diesel engine also in an axial section,

Fig. 3 is an explanatory and schematic front view of an engine according to Fig. l (or 2) and indicating at I-I the location of the sectional plane of Fig. 1 (or Fig. 2), and Fig. 4 is an enlarged view of the slip coupling embodied in the engine shown in Fig. l.

Referring to Fig. 1, the illustrated air-cooled two-cycle engine has a cooling blower 1 at one axial end and a high-speed scavenging blower 2 at the opposite end. The two blowers are located between the cylinder banks in front and in the rear respectively of the space occupied by the cylinders, the respective blower shafts being parallel to the crank shaft 3 of the engine. The cooling blower 1 is driven from the crank shaft 3 through a train of spur gears 4a, 4b, 4c and 4d. Mounted on one end of the crank shaft is a flywheel 5, while the other end drives the fuel injection pump 6. An electric generator 7 for lighting and the like auxiliary purposes is driven from the shaft of spur gear 4b.

The cooling blower 1 is of the axial type. It sucks air through a filter 8 into an enclosed space 9 from which the cooling air flows at both sides downward and along the exterior walls of the .,cylin ders before leaving the engine.

The scavenging blower 2 is ,of the radial .type and operates at a high revolving speed. Accordingly, the blower is driven through a high-ratio step-up transmission which includes the above-mentioned gear train and the shaft of the cooling blower and has an additional high-speed gear stage 10 immediately ahead of the scavenging blower. The blower shaft Pinion of this gear stage meshes with a spur gear 14 which is con nected with the rotor 15 of the cooling blower 1 by a shaft 16 coaxial with gear 14 and rotor 15. The shaft and the rotor 11 of the scavenging blower and the highspeed gear stage 10, including the shaft of the driving spur gear 14, are disposed and journalled in a common housing 13. This housing is centered at 16a in an opening of .the engine frame 12 and detachably secured to the frame. In the illustrated embodiment, the suction chamber of the scavenging blower is formed by a separate part 17 which, at 18, is centered at the engineframe and individually fastened thereto. The air inducted by the scavenging blower 2 at 17 is forced into an enclosed space 19 between the cylinder banks which communicates with the scavenging ducts of the engine cylinders.

Shafts 14 and 16 are coupled :by a spline fitting 20 so that the connection is established simply by stinking the spline and hub members of said fitting together when securing .the housing 13 to the engine frame, thus greatly facilitating the assembly. lnsertedbetween shaft 16 and the hollow shaft of gear 4a is a slip coupling 21. The slip coupling 21 is a torque transmitting ,QOE P i AIg 0f the pe l s iaaase d ri em dins hishe em nt changes in acceleration and is for the purpose of smoothing out the effect of torsional vibration in the engine crank shaft 3. As shown in the enlarged illustration of the slip couping 21 (see Fig. 4) the coupling comprises a sleeve bearing 40 surrounding the shaft 16 and forming part of the gear 40'. Driving connection between the gear 4d and the shaft 16 is accomplished through a cylindrical friction member 41 which is fixed to the sleeve bearing 40 and which has its outer cylindrical surface in frictional engagement with the inner cylindrical surface 42 of a drum structure 43 fixed to the shaft 16.

The invention is not limited to the above-exemplified application involving a scavenging blower but is likewise suitable in conjunction with other blowers, for instance, cooling blowers, superchargers, or blowers for cooling as well as supercharging. For example, in an engine as shown in Fig. 1, the rotor 15 of the cooling blower 1 and the immediately preceding gear pair 4d, 40 of the driving step-up transmission can be journalled in a common housing detachably secured to the engine frame in much the same way as shown and described with reference to the scavenging blower.

Fig. 2 shows an engine, for instance, also a two-cycle l-type diesel engine, whose centrifugal scavenging blower 22 is driven from the engine crank shaft 23 by a spur gear transmission. The rotor 24 of blower 22 and the adjacent gear stage 25 as well as the driven pinion 26 of the next following gear stage are journalled in a common housing 28 which is centered at 29 in an opening of the engine frame 27 and detachably secured to the frame. The intake portion 30 of the blower is designed as a separate part and at 31 centered and fastened to the engine frame. When the housing 28 is being assembled with the engine frame 27, the driven pinion 26 journalled in the housing enters into meshing engagement with the driving gear 32 of the transmission. The shaft 33 of gear 32 has a pinion 34 driven from a spur gear 35 which meshes with a spur gear 36 on the crank shaft 23 near the flywheel 37 of the engine,

In both illustrated engines, the frame openings at 18 or 31 for seating and centering the subassernbly of the biower housing are large enough to freely permit inserting the housing 13 or 28 into the centering holes at 16 and 29, respectively.

Various modifications other than those specifically referred to can, of course, be made and the invention can be applied to engines of other types and designs without departing from the objects and gist of the invention and within its essential features set forth in the claims annexed hereto.

I claim:

1. An air-cooled internal combustion engine, having V-arranged cylinders and comprising a crankcase structure, a crank shaft journalled in said structure, a cooling blower having a rotor and being disposed at one end of said structure, another blower for cylinder air having a rotor of higher speed than said rotor of said cooling blower and being disposed at the opposite end of said structure, said two rotors having respective axes parallel to that of said crank shaft, a spur gear transmission connecting said crank shaft with said rotor of said cooling blower, step-up transmission means having a driving gear and a driven gear, said driven gear being connected with said rotor of said other blower, a housing detachably secured to said structure, said transmission means and said rotor of said other blower being journalled in said housing independently of said structure, and a connecting shaft coupling said driving gear with said rotor of said cooling blower and being coaxial with said driving gear and said latter rotor.

2. An internal combustion engine according to claim 1, comprising a spline fitting. between said driven gear and said connecting shaft, said fitting being engageable and disengageable by attachment and removal respectively of said housing relative to said structure.

3. An internal combustion engine comprising a crankcase structure, a crank shaft iournalled in said structure, a cylinder-air blower forming part of said engine and having a rotary air impeller, a transmission for driving said air impeller from said crank shaft, said transmission having a low-speed portion and a high-speed portion, said low-speed portion being journalled in said structure and being operatively interconnected with said crank shaft, said high-speed portion comprising an impeller shaft fixed with respect to said rotary air impeller and a transmission gear shaft parallel to said impeller shaft, 21 first driven pinion gear on said transmission gear shaft, a drive gear on said transmission gear shaft, a second pinion gear on said impeller shaft, said drive gear being intermeshed with said second pinion gear, a gear housing detachably secured to said crankcase structure and providing a pair of axially spaced bearings for each of said impeller and transmission gear shafts, said impeller shaft and said gear shaft being journalled in said respective pairs of bearings independently of said structure and low-speed portion, whereby said housing and said high-speed portion of said transmission are removable as an operative unit from said lowspeed portion for balancing it as a subassembly.

References Cited in the file of this patent UNITED STATES PATENTS 835,277 Prayer et al. Nov. 6, 1906 1,440,685 Korvin-Kroukovsky Jan. 2, 1923 1,814,802 Herr July 14, 1931 1,884,321 Smith Oct. 25, 1932 1,903,979 Cappa Apr. 18, 1933 2,088,215 Podrabsliy July 27, 1937 2,098,718 Carninez et al. Nov. 9, 1937 2,168,726 Whittle Aug. 8, 1939 2,294,743 Funderburk Sept. 1, 1942 2,529,984 Wiederkehr et al. Nov. 14, 1950 FOREIGN PATENTS 494,141 Great Britain 1938 880,506 France Ian. 4, 1943 

